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Preparation and Properties of ZnO-based Diluted Magnetic Semiconductors

Author: WangQing
Tutor: HuZuoQi
School: Huazhong University of Science and Technology
Course: Microelectronics and Solid State Electronics
Keywords: Diluted magnetic semiconductors Zinc oxide First-principles Magnetic Doping
CLC: TN304.21
Type: Master's thesis
Year: 2011
Downloads: 23
Quote: 0
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Abstract


Decreasing size of today 's integrated circuit devices , electronic various quantum effects will become increasingly prominent , which spin properties of electrons will occupy a very important position . Spintronics , the spin-polarized current injected into the practical spintronic devices prerequisite . Both semiconductor and magnetic properties can dilute magnetic semiconductor spin injection effective . In this paper, from both theoretical and experimental aspects of the performance of the zinc oxide - based diluted magnetic semiconductor material . In theory , by first-principles calculation , the formation of point defects in the incorporation of intrinsic point defects in ZnO in two main the VO and Zni and Li Lii Properties of LiZn impact on the performance of ZnO . The results show that the above - mentioned various defects in ZnO alone can not induce ferromagnetism . Secondly, right separately Mn , Ni doped ZnO simulation . Found that mono - doped ZnO Mn Mn spin tend to reverse arrangement between the two Mn atoms also tend to close , the whole is easily formed on the antiferromagnetic clusters . This shows that individual Mn -doped ZnO with room temperature ferromagnetism in dilute magnetic semiconductor material is difficult to form . Ni - doped ZnO , Ni spin alignment of the energy of the system as a whole not individually doped Ni may also produce ferromagnetism . In the experiment , using the conventional solid -phase sintering prepared by the Ni -doped Li and Ni doped Mn and Li co-doped ZnO-based diluted magnetic semiconductor materials . Ferromagnetism found in the three materials . When the the magnetic doping ion concentration is less than 5 mol% , in the case of the same external magnetic field strength of the magnetization of the material along with the increasing concentration of the magnetic dopant ions enhanced. But the incorporation of a small amount of Li in the NiZnO material originally ferromagnetic material becomes no ferromagnetic , while higher Li concentration , NiZnO system appeared ferromagnetic . In in MnZnO , excess Li may weaken ferromagnetic MnZnO . This is mainly because the Li incorporation will significantly change the carrier concentration of the ZnO , and the ferromagnetism of the ZnO-based DMS may be derived contained the exchange interaction of the carrier media .

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CLC: > Industrial Technology > Radio electronics, telecommunications technology > Semiconductor technology > General issues > Material > Compound semiconductor > Oxide semiconductor
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